[juld0zer]

Seizure due to excessive friction would leave particles in the oil.
But if the engine cannot be rotated then the only other possibility is hydrolock, no? Aside from something jamming something else from moving. The intake manifold has to be elevated or removed so there is another possibility for foreign contaminants to enter.

Remove the spark plugs and then rotate the crank.

How about the oil cooler lines? Something can fall in there. If improperly tightened/seals not replaced then they can leak.

Big air pocket in the cooling system due to improper or no bleeding carried out post repair?

[lwgrenier]

Originally Posted by juld0zer

Seizure due to excessive friction would leave particles in the oil.
But if the engine cannot be rotated then the only other possibility is hydrolock, no? Aside from something jamming something else from moving. The intake manifold has to be elevated or removed so there is another possibility for foreign contaminants to enter.

Remove the spark plugs and then rotate the crank.

How about the oil cooler lines? Something can fall in there. If improperly tightened/seals not replaced then they can leak.

Big air pocket in the cooling system due to improper or no bleeding carried out post repair?

It isn't hydrolocked. Pulled the spark plugs and tried to rotate it. My car doesn't have an oil cooler so I'm thinking it must've been something getting into the ofh or yeah, maybe an air bubble. I'm having it towed to a specialist on the 27th. Hopefully he'll be able to tell me more.

[MartinWake]

Originally Posted by lwgrenier

It isn't hydrolocked. Pulled the spark plugs and tried to rotate it. My car doesn't have an oil cooler so I'm thinking it must've been something getting into the ofh or yeah, maybe an air bubble. I'm having it towed to a specialist on the 27th. Hopefully he'll be able to tell me more.

Im taking mine all apart rn

[vespa]

I'd guess a little fleck of rubber or dirt falls into the oil passage during the gasket change and then by freak chance it flows right into a rod bearing where it clogs the tiny passage. You wouldn't see shavings in the oil because there would be no oil flow to rinse the shavings out. The bearing would suddenly start rubbing and then spin and lock up within a very short time.

[TheMidnightNarwhal]

Originally Posted by vespa

I'd guess a little fleck of rubber or dirt falls into the oil passage during the gasket change and then by freak chance it flows right into a rod bearing where it clogs the tiny passage. You wouldn't see shavings in the oil because there would be no oil flow to rinse the shavings out. The bearing would suddenly start rubbing and then spin and lock up within a very short time.

Question is why would it happens more often to N55.

Is the N55 bottom end different a lot from the N54? They changed the rod bearing design right? Maybe there are now more prone to slight debris like you say.

[9krpmrx8]

It doesn't happen more often on the N55. There is zero data to indicate that.

[TheMidnightNarwhal]

Originally Posted by 9krpmrx8

It doesn't happen more often on the N55. There is zero data to indicate that.

I've barely seen any threads when searching about N54 rod bearings going RIP.

[Pladi]

Originally Posted by TheMidnightNarwhal

Question is why would it happens more often to N55.

Is the N55 bottom end different a lot from the N54? They changed the rod bearing design right? Maybe there are now more prone to slight debris like you say.

We could see more N55 fails because there are alot more of them out there. I dont know exactly how much more N55 were built but a quick look at the years tells you that N55 was used on alot more platforms. I would personally go as far as saying that there are probably 2-4 times the number. A wild guess so people are gonna freak out here at my response.

But its odd that most fails are with 2011 year. Something could be going on here. It def in my opinion, a oil delivery or restriction issue. I dont think the bearings are failing with good oil.(my opinion obv )

Is the N54 oil pump different ? OR the oil passage ? IS the filter housing design different with N54 ?

[9krpmrx8]

Originally Posted by TheMidnightNarwhal

I've barely seen any threads when searching about N54 rod bearings going RIP.

N54 failure posts are very common, especially on the FB forums. But forums thread posts are not statistics so they mean nothing really.

Originally Posted by Pladi

We could see more N55 fails because there are alot more of them out there. I dont know exactly how much more N55 were built but a quick look at the years tells you that N55 was used on alot more platforms. I would personally go as far as saying that there are probably 2-4 times the number. A wild guess so people are gonna freak out here at my response.

But its odd that most fails are with 2011 year. Something could be going on here. It def in my opinion, a oil delivery or restriction issue. I dont think the bearings are failing with good oil.(my opinion obv )

Is the N54 oil pump different ? OR the oil passage ? IS the filter housing design different with N54 ?

Your statement is nonsense, you have no idea how many N54's or N55's were made and you have no idea how many 2011 N55's have failed.

[TheMidnightNarwhal]

Originally Posted by 9krpmrx8

N54 failure posts are very common, especially on the FB forums. But forums thread posts are not statistics so they mean nothing really.




Your statement is nonsense, you have no idea how many N54's or N55's were made and you have no idea how many 2011 N55's have failed.

Every time I search it's just N55s.

And yes forums definitely give you a statistic idea. If there is a lot of posts on the subject it must mean something. It's still going to be somewhat proportional.

[Pladi]

Originally Posted by 9krpmrx8

N54 failure posts are very common, especially on the FB forums. But forums thread posts are not statistics so they mean nothing really.




Your statement is nonsense, you have no idea how many N54's or N55's were made and you have no idea how many 2011 N55's have failed.

[9krpmrx8]

Originally Posted by TheMidnightNarwhal

Every time I search it's just N55s.

And yes forums definitely give you a statistic idea. If there is a lot of posts on the subject it must mean something. It's still going to be somewhat proportional.

Somewhat proportional? BMW doesn't release model specific sales data but millions of E9X, E8X, E7X, E60, X6, F01, Z4, F2X, F06, F10, F11, F12, F15, F16, and many more, were sold. So the number of models that were equipped with the N54 and N55 is a shit ton so a couple of forum posts about failures that may or may not be related to design flaw in the engine doesn't mean shit. Especially when you consider most of the N55 failures I have seen on this forum have not been on stock cars, but fairly modified and tuned ones and on most the failure mode is mostly a guess as very few have had the engines torn apart and shared the results.

Now think of all the models that were equipped with the N54 or N55 in this time period and look at these numbers.

[9krpmrx8]

Originally Posted by Pladi

That is about what I expected your response to be.

[lwgrenier]

I think we can all agree opinions are opinions but how about we don’t turn this thread into a pissing contest. I took good care of my engine (since I bought the car) but it still failed. I may have to have the engine torn down to determine what the cause of failure was because there were no metal shavings in the oil. If that’s the case, I’ll let you what happened.

[TheMidnightNarwhal]

Originally Posted by 9krpmrx8

Somewhat proportional? BMW doesn't release model specific sales data but millions of E9X, E8X, E7X, E60, X6, F01, Z4, F2X, F06, F10, F11, F12, F15, F16, and many more, were sold. So the number of models that were equipped with the N54 and N55 is a shit ton so a couple of forum posts about failures that may or may not be related to design flaw in the engine doesn't mean shit. Especially when you consider most of the N55 failures I have seen on this forum have not been on stock cars, but fairly modified and tuned ones and on most the failure mode is mostly a guess as very few have had the engines torn apart and shared the results.

Now think of all the models that were equipped with the N54 or N55 in this time period and look at these numbers.

For sure but still, there is a trend going on.

[Pladi]

Originally Posted by lwgrenier

I think we can all agree opinions are opinions but how about we don’t turn this thread into a pissing contest. I took good care of my engine (since I bought the car) but it still failed. I may have to have the engine torn down to determine what the cause of failure was because there were no metal shavings in the oil. If that’s the case, I’ll let you what happened.

Yes we should be talking about specifics. No one has come FW with information of the engine and a basic analysis after the failure . If you can find some info that would be very helpful probably. All these rod bearing fails could be a bit different as far as root cause. But we have NOTHING.

[vuqle123]

Man, I'm thinking about doing the OFHG myself, but after reading these, it make me nervous.
May have to leave it to the workshop.

[Pladi]

Originally Posted by vuqle123

Man, I'm thinking about doing the OFHG myself, but after reading these, it make me nervous.
May have to leave it to the workshop.

I believe it should be the opposite. The shop messed up in this case. When you do it yourself you can be more careful. I did it twice and its hard to mess up honestly.

[9krpmrx8]

Originally Posted by TheMidnightNarwhal

For sure but still, there is a trend going on.

There is no data to indicate there is a trend of any kind.

[9krpmrx8]

Originally Posted by vuqle123

Man, I'm thinking about doing the OFHG myself, but after reading these, it make me nervous.
May have to leave it to the workshop.

It's so easy man. But it depends on your skill set I guess, but for me personally I don't let anyone touch my cars unless it is a recall or an insurance/warranty claim.

On my 2011 I just did the OFHG because I was replacing all the pulleys and the belt as preventative maintenance.


Just take your time and follow the service manual.

[vuqle123]

Originally Posted by Pladi

I believe it should be the opposite. The shop messed up in this case. When you do it yourself you can be more careful. I did it twice and its hard to mess up honestly.

Originally Posted by 9krpmrx8

It's so easy man. But it depends on your skill set I guess, but for me personally I don't let anyone touch my cars unless it is a recall or an insurance/warranty claim.

On my 2011 I just did the OFHG because I was replacing all the pulleys and the belt as preventative maintenance.


Just take your time and follow the service manual.

So you guys think better to do it myself? I do alot of repairing on big trucks and excavators. But for those trucks and machines, there's alot of room to work on and not much of the computer like BMW.

[Welcome to NBA Jam]

Originally Posted by TheMidnightNarwhal

For sure but still, there is a trend going on.

There is no statistical evidence of a trend. There are a known handful of outliers who experienced a specific failure. That is not the definition of a trend. We don't have enough data to create even the most rudiamentary of models to suggest any correlation of factors for failure.